IATA predicts passenger traffic in 2009 will fall for the first time since 2001
The global economic downturn has deeply reduced the amount of freight carried around the world by aircraft, says an industry body.
The International Air Transport Association (Iata) saw air cargo go into "freefall" in December, with a year-on-year fall of 22.6% in traffic.
The "unprecedented" figure is worse than the 14% drop after the 9/11 terror attacks on New York.
Now Iata is warning of a tough year for passenger airlines and freight firms.
Iata says that during 2009 there will be declines of 3% in air passenger traffic and 5% in freight cargo carried.
"2009 is shaping up to be one of the toughest ever years," said Iata director general Giovanni Bisignani.
In a further sign of the economic crisis hitting the aviation industry, Russia's S7 became the first airline to cancel an order for Boeing's 787 Dreamliner.
About 35% of international goods trade is by air, says Iata. In 2008, cargo traffic fell 4% compared with a 4.3% increase in 2007, the body said, its first annual fall since 2001.
"Even in September 2001, when much of the global fleet was grounded, the decline was only 13.9%," said Mr Bisignani.
Iata said the figures reflected a fall in export and import volumes being reported across Asia, North America and Europe.
Overall, the industry body expects the economic crisis to cut $35bn from air industry revenues in 2009.
Last year passenger traffic grew by just 1.6%, down from the 7.4% rise a year before.
"Airlines are struggling to match capacity with fast-falling demand," said Mr Bisignani.
"Until this comes into balance, even the sharp fall in fuel prices cannot save the industry from drowning in red ink."
However the chief executive of Airbus says that he sees no need for a government bail-out of the airline industry.
Speaking at the World Economic Forum, he said the sector is relying on governments to sort out the banks.
"What our industry needs is first and foremost a functioning financial system," Tom Enders told the BBC.
It was reported earlier in the week that the French government was considering measures to help airlines to buy new aircraft.
The international airline industry lost $5bn (£3.3bn) last year, Iata said, confirming an earlier estimate.